桂花种子的^(60)Co-γ射线辐射敏感性及半致死剂量研究

Sensitivity of Osmanthus fragrans Seeds to ^(60)Co-γ Radiation and Its Medial Lethal Doses in Radiation Breeding

以金桂、银桂种子为试材,采用不同剂量^(60)Co-γ射线辐射种子,观察辐射对桂花种子发芽率及胚根生长的影响,以种子50%发芽率为基准,通过直线回归方程计算半致死剂量,以研究桂花辐射诱变育种,探讨桂花种子辐射剂量的问题,选育具有较高观赏价值的桂花优良新品种。结果表明:^(60)Co-γ射线辐射可引起桂花种子胚根缩短、发芽率降低;金桂与银桂种子的辐射半致死剂量分别为123.807、118.381Gy,最大辐照量为250Gy。辐射剂量与金桂和银桂种子的发芽率间呈高度负相关,相关系数分别为r=-0.910、r=-0.934。金桂种子辐射敏感性高于银桂种子。

In order to study the radiative mutation breeding of Osmanthus fragrans,explore the radiation dosages of Osmanthus fragrans and select new variety of Osmanthus fragrans having high ornamental value,the Osmanthus fragrans seeds from two different varieties（var.thunbergii Makino and var.latifolius Makino）were treated with different dosages of 60Co-γray（0,50,100,150,200,250 and 300Gy）,and the seed germination rate and radicle growth were observed.Based on the germination rate 50%,LD50 doses of 60Co-γradiation for the seeds were calculated using linear regression equation.The results showed that 60Co-γradiation caused the seeds radicle length shortened,lower germination rate.LD50 doses of 60Co-γradiation for the seeds of var.thunbergii Makino and var.latifolius Makino were123.807 Gy and 118.381 Gy respectively.Their maximum radiation dose was 250 Gy.The seeds germination rate of Osmanthus fragrans had a high negative correlation with radiation dose,the correlation coefficient was r=-0.910,r=-0.934,respectively.The radiation sensitivity of var.thunbergii Makino seeds was higher than var.latifoliusMakino seeds.